Case #170 – December, 2005

A lab worker discovered an unlabeled box of 20 pathology slides, which appeared to be stained with hematoxylin and eosin (H & E). The slides were examined to determine what was on them. Figure A shows what was seen on one of the slides at 200× magnification. What is your identification? Based on what criteria?

Figure A

The object shown was the encapsulated larva of a nematode in the genus, Trichinella. The lab worker later found the key to the slide tray, which stated the slide showed Trichinella spiralis. A species determination should not be made based on just the specimen in this case; geographic, biologic, and clinical information should be considered before a species is given.